Muslim Calendar based Holidays Rules allow you to define holidays which are based on the Muslim Calendar.

The structure of Muslim Holidays is almost always a simple Month-Day pair ...

End of Ramadan, Singapore

... except for the Jumatul Bidah.

Jumatul Bidah, Bangladesh

The complication is the determination of Muslim holidays is which Muslim calendar to use. Q++Studio contains the a pre-programmed list of the Muslim calendars used by almost all the countries where Muslim holidays are real non-working public holidays.